Method and apparatus for the direct production of scale-free thin metal strip

ABSTRACT

A method and apparatus for the direct production, from molten metal, of scale-free thin metal strip. Hot thin metal strip exiting a continuous caster system is directed to a reducing chamber wherein a reducing gas reduces strip surface oxides while the cast metal strip is at an elevated temperature from retained heat from the molten metal. A cooling unit following the reducing chamber is used to cool the strip to a temperature below about 150° C. prior to exposing the strip to an oxidizing atmosphere. In various embodiments of the invention, strip thickness is reduced with use of hot and cold rolling mills and the scale-free surface of the strip is coated with protective coatings.

FIELD OF THE INVENTION

[0001] The present invention is a method and apparatus for the directproduction from molten metal of scale-free, finished gage, metal stripby continuous casting of a hot thin strip. Surface oxide removal is witha reducing gas while the cast hot thin metal strip is at an elevatedtemperature from retained heat of the molten metal.

BACKGROUND OF THE INVENTION

[0002] Production of flat rolled steel strip, by currentstate-of-the-art processes, is carried out by continuously castingrefined steel into a thin slab, followed by hot rolling of the slab toreach a thickness which can be put into coil form for subsequentprocessing. In that process, the surface of the coiled, hot rolled steelis heavily oxidized from processing steps carried out at an elevatedtemperature while being exposed to the atmosphere. Such oxides (scale)typically consist of Fe₂O₃, Fe₃O₄ and FeO. A next step in the productionof the flat rolled steel strip typically involves removing the oxides byprocessing the strip in an acid pickling solution prior to rolling thestrip to finished gage in a cold rolling mill.

[0003] Current methods of processing flat rolled steel strip require useof hot and cold rolling mill equipment requiring significant capitalexpenditures, large amounts of energy for operating, and a large plantfacility for its installation. In addition, use of acid picklingsolutions for removing surface oxides and disposal of spent acidsolution, present environmental concerns which are resulting in morestringent regulations and increased costs for disposal.

[0004] In an effort to reduce or eliminate hot and cold rolling steps,methods are being developed to continuously cast thin strip whichapproaches finished gage thickness. Oxides are still present on thesurface however and problems associated with oxide removal with use ofacid pickling solutions continue to exist.

OBJECT OF THE INVENTION

[0005] It is the object of the present invention to provide a processfor producing finished gage thin steel strip free of surface oxides,without the use of acid pickling solutions, and without the use ofextensive hot and cold rolling equipment.

SUMMARY OF THE INVENTION

[0006] The present invention is a method and apparatus for the directproduction of scale-free thin metal strip from molten metal bycontinuously casting molten metal into a hot thin metal strip and, whilethe cast strip still retains heat from the molten metal, passing itthrough a chamber containing a reducing gas to remove oxides from thesurface of the strip so as to produce a metal strip free of surfaceoxides. The hot strip is then cooled to a temperature below about 150°C. prior to exposing the strip surface to any oxidizing atmosphere. Inother embodiments of the invention, hot rolling of the hot thin metalstrip and/or cold rolling of the cooled thin metal strip is carried outto reduce the strip thickness and modify mechanical properties of themetal. In still other embodiments of the invention the surface of thecooled thin metal strip is brushed, re-textured or coated with aprotective or decorative coating.

[0007] Other specific features of the invention are described in moredetail with reference being made to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008]FIG. 1 is a schematic illustration of the process and apparatus ofthe invention for producing scale-free thin strip;

[0009]FIG. 2 is a schematic illustration of an embodiment of the processand apparatus of the invention for producing scale-free thin strip whichincorporates a hot-rolling step prior to strip cleaning;

[0010]FIG. 3 is a schematic illustration of an embodiment of the processand apparatus of the invention for producing scale-free thin strip whichincorporates a cold-rolling operation following a strip cooling step;

[0011]FIG. 4 is a schematic illustration of an embodiment of the processand apparatus of the invention for producing scale-free thin strip whichincorporates means for shearing the strip into discreet pieces;

[0012]FIG. 5 is a schematic illustration of an embodiment of the processand apparatus of the invention for producing scale-free thin strip whichincorporates a surface re-texturing step; and

[0013]FIG. 6 is a schematic illustration of an embodiment of the processand apparatus of the invention for producing scale-free thin strip whichincorporates an accumulating device following a continuous castersystem.

DETAILED DESCRIPTION OF THE INVENTION

[0014] In FIGS. 1-6, numeral 10 generally denotes a thin stripcontinuous caster system for producing hot thin metal strip having athickness of between about 0.5 and 4 mm. Molten metal 12, a product ofan electric arc furnace, a BOF process, or other molten metal source iscontinuous cast into hot thin metal strip 14 which exits final castingrolls 16 of the continuous caster system. The molten metal, continuouslycast into the hot thin metal strip, can be steel, stainless steel,copper, or other metals; however, the invention is disclosed in relationto production of scale-free thin steel strip.

[0015] The hot thin steel strip 14 exiting continuous caster system 10retains heat from molten metal 12 and the continuous caster system ispreferably controlled to discharge a hot thin metal strip having asurface temperature above about 400° C. The surface of the hot thinmetal strip, which is usually exposed to a liquid cooling medium and tothe atmosphere while being cast, is heavily oxidized with a surfaceoxide containing Fe₂O₃, Fe₃O₄, FeO, or combinations of those oxides,depending on conditions during the casting operation.

[0016] The hot thin metal strip 14, (FIG. 1) having a surfacetemperature of above about 400° C., enters reducing chamber 18, whichencloses a reducing gas atmosphere. An example of a reducing chamber 18is the type described in copending U.S. patent application Ser. No.09/144,003 filed Aug. 31, 1998 in the name of Stephen L. Feldbauer, andin copending U.S. patent application Ser. No. filed Jun. 1, 2000 in thenames of Stephen L. Feldbauer and Brian Braho, both of which areassigned to the assignee of the present invention and both of which areincorporated herein by reference. Reducing chamber 18 contains areducing gas such as hydrogen or carbon monoxide, with hydrogen beingthe preferred gas. Hot thin metal strip 14 moves through chamber 18 in adirection indicated by arrow 20 while movement of the reducing gas isgenerally in an opposite direction as indicated by arrows 22. The gasexits chamber 18 by way of vent 24 which can include a combustion means,such as a flame, for combusting unconsumed reducing gases exiting thechamber so as to provide for safe operation. Reduction of the stripsurface oxides in the reducing chamber is optimized by providing avigorous application of reducing gas to the surface of the strip. In apreferred embodiment the reducing gas is continuously introduced intothe chamber through apertures in gas manifolds and directed toward thestrip surface at a velocity which creates turbulence on impact with thestrip. The reducing action of the gas on the surface oxides acts toreduce the oxides as well as undermine and loosen particles of oxide onthe strip surface thus not requiring every oxide particle or oxidemolecule to completely react with the reducing gas. Loosened oxides canbe easily removed downstream by mechanical methods such as brushing,described below. To assure good contact of the reducing gas with strip14, fans (not shown) can be placed within the reducing chamber toprovide turbulence to the gas so as to optimize the reduction reaction.

[0017] For proper operation of the reducing process, the surfacetemperature of hot thin metal strip 14 is above about 400° C. Thereducing reaction must take place during a very short period of time asthe strip may be moving through the chamber at a speed up to 750 feetper minute. In a preferred embodiment, the hot thin metal strip is atthe preferred temperature solely from heat retained in the strip fromthe molten metal continuous casting operation. Strip cooling iscontrolled during casting in continuous caster system 10, to providesufficient heat for oxide removal in reducing chamber 18.

[0018] Means can be provided within reducing chamber 18 to heat the hotthin metal strip if the strip is not at the preferred temperature. InFIG. 1, radiant heaters 26 are shown, as an example, for providing heatto the strip. Heaters 26 may be used during continuous caster start-upperiods or slow-down periods, which might be caused by caster operatingproblems, so as to provide for the proper temperature for the stripsurface. Heaters 26 are also necessary if a strip accumulating means isprovided intermediate strip caster system 10 and reducing chamber 18. Astrip accumulating means is described below. In certain plants, use ofheaters 26 may be required on a continual basis if optimum continuouscaster operation does not allow a cast hot thin metal strip exittemperature as preferred.

[0019] In line, immediately following reducing chamber 18, is coolingunit 28 wherein hot thin metal strip 14 is cooled to a temperature belowabout 150° C. in an inert or reducing atmosphere. A reducing atmosphereis preferred as additional reduction of surface oxides can take placeduring an initial portion of the cooling process while the thin metalstrip is still at an elevated temperature. Cooling unit 28 is preferablyconnected directly to reducing chamber 18 in order that thin metal strip14 is not subjected to the atmosphere while at an elevated temperature.

[0020] Cooling is carried out in cooling unit 28 by introducing coolinggas through manifolds 30 and directing it toward the strip surface. Thecooling gas is preferably an inert gas such as nitrogen combined with areducing gas such as hydrogen. Seal 32 at the exit end of cooling unit28 and seal 34 at the entrance end of reducing chamber 18 preventoxidizing gases of the atmosphere from entering the system. A positivepressure within the reducing chamber and cooling unit helps to preventthe entrance of oxidizing gases.

[0021] As previously described, non-adhering particles of oxides can bepresent on the strip surface following the reduction reaction. Removalof those particles is accomplished with use of brushing unit 36 whichprovides brushes to act on the top and bottom surface of the cooled thinmetal strip. Other suitable means can be employed for removal of theparticles.

[0022] The scale-free cooled thin metal strip exiting brushing unit 36is susceptible to oxidation, and, if not scheduled for immediateadditional processing, can have an oil coating applied at coatingstation 38 prior to coiling at strip coiler 40. Alternative procedurescan consist of applying other coatings at coating station 38 such as aprotective organic coating applied with an organic coating unit or othermore durable coatings such as hot-dipped galvanizing applied with ahot-dipped galvanizing unit or electrolytically plated coatings appliedwith an electrolytic plating unit.

[0023] The process, as described in reference to FIG. 1, providesscale-free metal strip at a finished gage substantially equal to thegage of the continuously cast thin metal strip exiting continuous castersystem 10. FIG. 2 depicts a production system wherein at least onehot-rolling mill 42 is provided intermediate continuous caster system 10and reducing chamber 18. The configuration depicted in FIG. 2 provides amethod and apparatus to conveniently reduce the finished gage of thestrip from the thickness of the strip exiting the continuous castersystem. Use of the hot-rolling mill, which results in a decrease instrip temperature, may require additional use of heaters 26 in reducingchamber 18 to provide the desired oxide reducing temperature; or,alternatively, the strip continuous caster system 10 can be controlledto exit the strip at a temperature higher than that preferred for thestrip in reducing chamber 18.

[0024] In FIG. 3, a method is depicted wherein at least one cold-rollingmill 44 is provided intermediate brushing unit 36 and coating station38. Locating cold-rolling mill 44 following brushing unit 36 ispreferred so as not to embed any loosened oxide particles into thesurface of the metal strip during cold rolling.

[0025] The inclusion of cold-rolling mill 44 in the processing lineenables production of a thin metal strip having a finished gage lessthan that of the strip exiting continuous caster system 10. Use ofcold-rolling mill 44 can also provide a means for modifying mechanicalproperties of the strip. Use of cold-rolling mill 44 in combination withthe hot-rolling mill, in a single processing line, can enable productionof scale-free thin metal strip of various thicknesses having a range ofmechanical properties. Thicknesses ranging from about 0.3 to 3.5 mm arepossible using solely the hot-rolling or cold-rolling step, or thecombined hot-rolling and cold-rolling step.

[0026]FIG. 4 depicts a processing line wherein discreet pieces ofscale-free thin metal 46 are produced. The processing line for producingdiscreet pieces includes bridal rolls 48, or other means, formaintaining strip tension, followed by severing means such as shear 50for severing the continuous strip into discreet pieces. Configuration ofthe processing line prior to shear 50 can be as described in any of theprevious embodiments.

[0027] In FIG. 5, a processing station 52 is depicted having means forre-texturing the surface of thin metal strip 14. The re-textured surfacecan include, for example, an etched surface, obtained with use of asurface etching unit, a “brushed” surface appearance, obtained forexample, with a wire brushing unit, an embossed surface, obtained withuse of an embossing unit, etc. Although no rolling mill is shown in FIG.5, rolling mills as depicted in configurations described above arepossible.

[0028]FIG. 6 depicts a scale-free thin metal strip processing linewherein a strip accumulating means is provided as a buffer betweencontinuous caster system 10 and reducing chamber 18. Coil box 54enclosing a strip coiler and a strip uncoiler can be used routinelyduring processing or can be by-passed and used solely when downstreamequipment repairs, maintenance, or delays occur. Although means can beprovided to prevent loss of strip temperature while in coil box 54, useof heaters 26 in reducing chamber 18 would most likely be necessary.Other suitable strip accumulating devices can also be used.

[0029] While specific materials, parameters, and processing steps havebeen set forth for purposes of describing embodiments of the invention,various modifications can be resorted to, in light of the aboveteachings, without departing from Applicant's novel contributions;therefore in determining the scope of the present invention referenceshould be made to the appended claims.

What is claimed is:
 1. A method for the direct production of scale-freethin metal strip from molten metal, comprising: casting hot thin metalstrip from molten metal in a thin strip continuous casting system;passing the hot thin metal strip, while the same still retains heat fromthe molten metal, through a reducing chamber; contacting the hot thinmetal strip in the reducing chamber with a reducing gas to reduce oxideson the surfaces of the strip; and cooling the hot thin metal strip to atemperature of below about 150° C., prior to exposure to an oxidizingatmosphere, to provide a cooled, thin metal strip.
 2. The method for thedirect production of scale-free thin metal strip from molten metal asdefined in claim 1, wherein the hot thin metal strip retains sufficientheat from the molten metal to be at a temperature of above about 400° C.upon passing through the reducing chamber.
 3. The method for the directproduction of scale-free thin metal strip from molten metal as definedin claim 1, wherein the hot thin metal strip is passed directly from thereducing chamber to a cooling unit for cooling without exposure to anoxidizing gas.
 4. The method for the direct production of scale-freethin metal strip from molten metal as defined in of claim 1, wherein thecooled thin metal strip is formed into a coil.
 5. The method for thedirect production of scale-free thin metal strip from molten metal asdefined in claim 1, wherein the hot thin metal strip is decreased inthickness to a predetermined gage by hot rolling prior to passing thestrip through the reducing chamber.
 6. The method for the directproduction of scale-free thin metal strip from molten metal as definedin claim 1, wherein, after cooling to a temperature below about 150° C.,the cooled thin metal strip is decreased in thickness to a predeterminedgage by cold rolling.
 7. The method for the direct production ofscale-free thin metal strip from molten metal as defined in claim 1,wherein said hot thin metal strip has a thickness of between about 0.5to 4 mm.
 8. The method for the direct production of scale-free thinmetal strip from molten metal as defined in claim 5 wherein, afterdecreasing in thickness, the cooled thin metal strip has a thickness ofbetween about 0.3 to 3.5 mm.
 9. The method for the direct production ofscale-free thin metal strip from molten metal as defined in claim 6wherein, after decreasing in thickness, the cooled thin metal strip hasa thickness of between about 0.3 to 3.5 mm.
 10. The method for thedirect production of scale-free thin metal strip from molten metal asdefined in claim 1, wherein the thin metal strip is brushed aftercooling.
 11. The method for the direct production of scale-free thinmetal strip from molten metal as defined in claim 10, wherein thebrushed thin metal strip is decreased in thickness to a predeterminedgage by cold rolling.
 12. The method for the direct production ofscale-free thin metal strip from molten metal as defined in claim 10,wherein the brushed thin metal strip has a coating applied to at leastone of the surfaces.
 13. The method for the direct production ofscale-free thin metal strip from molten metal as defined in claim 12,wherein the coating is oil.
 14. The method for the direct production ofscale-free thin metal strip from molten metal as defined in claim 1,wherein the thin metal strip is sheared into discreet pieces aftercooling.
 15. The method for the direct production of scale-free thinmetal strip from molten metal as defined in claim 1, wherein the thinmetal strip has a coating applied to at least one of the surfaces aftercooling.
 16. The method for the direct production of scale-free thinmetal strip from molten metal as defined in claim 15, wherein thecoating is oil.
 17. The method for the direct production of scale-freethin metal strip from molten metal as defined in claim 1, wherein, aftercooling, at least one of the surfaces of the cooled thin metal strip isre-textured.
 18. The method for the direct production of scale-free thinmetal strip from molten metal as defined in claim 1, wherein the hotthin metal strip cast from the continuous caster system is accumulatedprior to passing the strip through the reducing chamber to reducesurface oxides.
 19. The method for the direct production of scale-freethin metal strip from molten metal as defined in claim 1, wherein, thehot thin metal strip is decreased in thickness to a predetermined gageby hot rolling prior to passing the strip through the reducing chamber,and following cooling to a temperature below about 150° C. the cooledthin metal strip is further decreased in thickness to a predeterminedgage by cold rolling.
 20. The method for the direct production ofscale-free thin metal strip from molten metal as defined in claim 1,wherein the hot thin metal strip, while retaining heat from the moltenmetal, is below about 400° C., and is heated to at least about 400° C.upon passing through the reducing chamber.
 21. The method for the directproduction of scale-free thin metal strip from molten metal as definedin claim 20, wherein the hot thin metal strip is passed directly fromthe reducing chamber to a cooling unit without exposure to an oxidizinggas.
 22. The method for the direct production of scale-free thin metalstrip from molten metal as defined in claim 20, wherein the cooled thinmetal strip is formed into a coil.
 23. The method for the directproduction of scale-free thin metal strip from molten metal as definedin claim 20, wherein the hot thin metal strip is decreased in thicknessto a predetermined gage by hot rolling prior to passing through thereducing chamber.
 24. The method for the direct production of scale-freethin metal strip from molten metal as defined in claim 20, wherein,after cooling to a temperature below about 150° C., the cooled thinmetal strip is decreased in thickness to a predetermined gage by coldrolling.
 25. The method for the direct production of scale-free thinmetal strip from molten metal as defined in claim 20, wherein said hotthin metal strip has a thickness of between about 0.5 to 4 mm.
 26. Themethod for the direct production of scale-free thin metal strip frommolten metal as defined in claim 23 wherein, after decreasing inthickness, the cooled thin metal strip has a thickness of between about0.3 to 3.5 mm.
 27. The method for the direct production of scale-freethin metal strip from molten metal as defined in claim 24 wherein, afterdecreasing in thickness, the cooled thin metal strip has a thickness ofbetween about 0.3 to 3.5 mm.
 28. The method for the direct production ofscale-free thin metal strip from molten metal as defined in claim 20,wherein the thin metal strip is brushed after cooling.
 29. The methodfor the direct production of scale-free thin metal strip from moltenmetal as defined in claim 20, wherein the thin metal strip is shearedinto discreet pieces after cooling.
 30. The method for the directproduction of scale-free thin metal strip from molten metal as definedin claim 20, wherein the thin metal strip has a coating applied to atleast one of the surfaces after cooling.
 31. The method for the directproduction of scale-free thin metal strip from molten metal as definedin claim 30, wherein the coating is oil.
 32. The method for the directproduction of scale-free thin metal strip from molten metal as definedin claim 20, wherein, after cooling, at least one of the surfaces of thecooled thin metal strip is re-textured.
 33. A method for the directproduction of scale-free thin metal strip from molten metal, comprising:casting hot thin metal strip from molten metal in a thin stripcontinuous casting system; passing the hot thin metal strip, while thesame still retains heat from the molten metal, directly to, and through,a reducing chamber, while the hot thin metal strip retains sufficientheat from the molten metal to be at a temperature of above about 400°C.; contacting the hot thin metal strip in the reducing chamber with areducing gas to reduce oxides on the surfaces of the strip; passing thehot thin metal strip directly from the reducing chamber to a coolingunit for cooling without exposure to an oxidizing gas; cooling the hotthin metal strip to a temperature of below about 150° C., prior toexposure to an oxidizing atmosphere, to provide a cooled thin metalstrip; and forming the cooled thin metal strip into a coil.
 34. Themethod for the direct production of scale-free thin metal strip frommolten metal as defined in claim 33, wherein the hot thin metal strip isdecreased in thickness to a predetermined gage by hot rolling prior topassing the strip through the reducing chamber.
 35. The method for thedirect production of scale-free thin metal strip from molten metal asdefined in claim 33, wherein, after cooling to a temperature below about150° C., the cooled thin metal strip is decreased in thickness to apredetermined gage by cold rolling.
 36. An apparatus for the directproduction of scale-free thin metal strip from molten metal, comprising:a thin strip continuous caster system for producing a hot thin metalstrip, a reducing chamber, enclosing a reducing gas, arranged to receivethe hot thin metal strip, to reduce metal oxides on the strip surfaces,and a cooling unit, provided with a non-oxidizing gas, arranged toreceive the hot thin metal strip following reduction of surface metaloxides, to cool the hot thin metal strip to a temperature below about150° C. prior to exposure to an oxidizing atmosphere.
 37. The apparatusfor the direct production of scale-free thin metal strip from moltenmetal as defined in claim 36, wherein the cooling unit is disposed inrelation to the reducing chamber so as to receive the hot thin metalstrip without exposing the strip to an oxidizing atmosphere.
 38. Theapparatus for the direct production of scale-free thin metal strip frommolten metal as defined in claim 36, wherein said reducing chamberincludes heating means for heating the hot thin metal strip to at leastabout 400° C.
 39. The apparatus for the direct production of scale-freethin metal strip from molten metal as defined in claim 36, furtherincluding a strip coiler, arranged to receive the cooled thin metalstrip, to form the strip into a coil.
 40. The apparatus for the directproduction of scale-free thin metal strip from molten metal as definedin claim 36, further including a hot-rolling mill, disposed intermediatethe continuous caster system and the reducing chamber, for reducing thethickness of the hot thin metal strip to a predetermined gage.
 41. Theapparatus for the direct production of scale-free thin metal strip frommolten metal as defined in claim 36, further including a cold-rollingmill, disposed to receive the cooled thin metal strip, for reducingthickness of the cooled thin metal strip to a predetermined gage. 42.The apparatus for the direct production of scale-free thin metal stripfrom molten metal as defined in claim 36, further including a means forbrushing surfaces of the thin metal strip following cooling in thecooling unit.
 43. The apparatus for the direct production of scale-freethin metal strip from molten metal as defined in claim 36, furtherincluding means for shearing the thin metal strip into discreet piecesfollowing cooling in the cooling unit.
 44. The apparatus for the directproduction of scale-free thin metal strip from molten metal as definedin claim 36, further including means for coating the thin metal stripfollowing cooling in the cooling unit.
 45. The apparatus for the directproduction of scale-free thin metal strip from molten metal as definedin claim 44, wherein said means for coating is a coating device selectedfrom at least one of: an oil coater, a hot-dipped galvanizing unit, anelectrolytic plating unit, and an organic coating unit.
 46. Theapparatus for the direct production of scale-free thin metal strip frommolten metal as defined in claim 36, further including means forre-texturing the thin metal strip following cooling in the cooling unit.47. The apparatus for the direct production of scale-free thin metalstrip from molten metal as defined in claim 46, wherein said means forre-texturing the thin metal strip is a re-texturing device selected fromat least one of: a surface etching unit, a wire brushing unit, and anembossing unit.
 48. The apparatus for the direct production ofscale-free thin metal strip from molten metal as defined in claim 36,further including at least one processing device selected from at leastone of: a hot-rolling mill, a cold-rolling mill, a brushing unit, ashearing unit, a coiler, a coater, and a re-texturing unit.
 49. Theapparatus for the direct production of scale-free thin metal strip frommolten metal as defined in claim 36, wherein said reducing chamberincludes means for providing turbulence to the reducing gas acting onthe oxides of the thin strip surface.
 50. The apparatus for the directproduction of scale-free thin metal strip from molten metal as definedin claim 36, further including means for accumulating hot thin metalstrip cast in the continuous caster system, situated between thecontinuous caster system and the reducing chamber.
 51. The apparatus forthe direct production of scale-free thin metal strip from molten metalas defined in claim 50, wherein the means for accumulating hot thinmetal strip comprises a coil box, including a coiler and an un-coiler.52. An apparatus for the direct production of scale-free thin metalstrip from molten metal, comprising: a thin strip continuous castersystem for producing a hot thin metal strip; a reducing chamber,enclosing a reducing gas, arranged to receive the hot thin metal strip,to reduce metal oxides on the strip surfaces; a cooling unit, disposedin relation to the reducing chamber so as to receive the hot thin metalstrip without exposing the strip to an oxidizing atmosphere, providedwith a non-oxidizing gas, arranged to receive the hot thin metal stripfollowing reduction of surface metal oxides, to cool the hot thin metalstrip to a temperature below about 150° C. prior to exposure to anoxidizing atmosphere; and a strip coiler arranged to receive coated thinmetal strip, to form the strip into a coil.
 53. The apparatus for thedirect production of scale-free thin metal strip from molten metal asdefined in claim 52, further including a hot-rolling mill, disposedintermediate the continuous caster system and the reducing chamber, forreducing the thickness of the hot thin metal strip to a predeterminedgage.
 54. The apparatus for the direct production of scale-free thinmetal strip from molten metal as defined in claim 52, further includinga cold-rolling mill, disposed to receive the cooled thin metal strip,for reducing thickness of the cooled thin metal strip to a predeterminedgage.